Results: A decrease in blood pressure (>5 mmHg; P < 0.05) was observed after the fish but not the fish oil. The change in waist to hip ratio also favoured the fish intervention. Resting heart rate fell by a similar amount on both interventions, and the omega-3 index increased significantly on both; from 6% to 7–8% (P < 0.01). Blood lipids did not improve on either arm.

Conclusions: In Australians with coronary heart disease, 1 g/day of long-chain omega-3 polyunsaturated fatty acid from fish or supplements over 12 weeks was effective in increasing the omega-3 index. Fish intake may have additional cardiovascular benefits beyond the omega-3 effect as evidenced by the substantial blood pressure reduction following the fish arm warranting examination in a larger study.